55 research outputs found

    Investigation of the natural sand transport on the Belgian Continental shelf: BUDGET (<u>B</u>eneficial <u>u</u>sage of <u>d</u>ata and <u>g</u>eo-<u>e</u>nvironmental <u>t</u>echniques)

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    On the Belgian continental shelf (BCS), a variety of sediment dynamical studies have been performed both by governmental organisations and research institutions. Each study proposed to achieve a better insight in the sediment dynamical processes taking place on a specific spatial scale and during a particular time period. However, all these studies contain a piece of information, which contribute to the global sediment dynamical behaviour of the sediments of the BCS.In the course of the project, an overview has been produced of all these studies. Most of the data has been re-evaluated and the results were compiled in a synthesis map to characterise the natural sand transport on the Belgian continental shelf. The map indicates the general nature of the surficial sediments superimposed with the occurrence of larger bedforms. Additionally, areas are indicated where the thickness of the quaternary deposits is less than 2.5 mas these sediments might take part in the sediment transport process. To illustrate the hydrodynamics of the BCS, current ellipses have been selected based on modelling results on a 750 mgrid resolution and locations were indicated where current meter or other hydrodynamic data has been collected. Towards the directions of sediment transport, a variety of arrows are drawn whereby a distinction is made between transport vectors based on geo-environmental methods and those based on in-situ sediment transport measurements and on modelling results. If available, quantities are added uniformised in tonnes/m/day.The study also included a critical analysis of the data and methods used. The deduction of residual transport directions was evaluated on the basis of the asymmetry of bedforms, tracer experiments, sediment differentiation, current and suspended sediment concentration measurements and based on numerical sediment transport modelling. Evaluation criteria were set-up regarding the different space and time scales involved. The influence of hydro-meteorological conditions on the sediment dynamics was discussed.The results allowed defining gaps in the present knowledge and including recommendations for future research and propositions for an integrated research programme on the Belgian continental shelf. Main emphasis is put on an efficient mapping of the seafloor including the set-up of an automated characterisation of seabed sediments albeit combined with a suitable sampling strategy. Regarding hydrodynamical and sand transport measurements, the development of a multi-sensor bottom frame is recommended including a realistic quantification of sediment fluxes through the water column.To enhance the efficiency and practical use of seabed data, the set-up of an overall Geographical Information System (GIS) is highly recommended including guidelines and protocols on the prerequisites of mapping and sampling projects since this would largely facilitate the set-up and evaluation of environmental impact assessments. The project largely benefited from contributions from foreign researchers from France, England and the Netherlands

    Modern customers and open universities: can open universities develop a course model in which students become the co-creators of value?

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    Marketing specialists have recently redefined the roles customers and enterprises play in the economy. Modern customers are connected, informed, mobile, educated and internationally oriented. They seek enterprises that empower them to co-construct personalised experiences. This view of the customer鈥揺nterprise relationship has a great impact on the ways markets function. Open universities can apply developed principles in marketing to optimise the value of their degree programmes. A capita selecta course within the Open University of the Netherlands has given students the opportunity to personalise learning. Within the limits of the formal Master programme, students were encouraged to define personal learning goals, study tasks and work to be delivered and formally assessed. In this paper, the course is analysed according to the principles of customer鈥揺nterprise relations, and I explore the question: can open universities develop a course model in which students become the co-creators of value

    Optimizaci贸n del tratamiento farmacol贸gico en pacientes con disfunci贸n sist贸lica severa del ventr铆culo izquierdo en una unidad de insuficiencia cardiaca: implicaciones en la indicaci贸n de un desfibrilador autom谩tico implantable en prevenci贸n primaria y factores predictores de ausencia de remodelado reverso del ventr铆culo izquierdo

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    Distance education is going through a paradigm shift from the second to the third generation. In the first generation (correspondence education) teachers were craftsmen who coupled traditional learning materials to self-made personalised lessons that they mailed to their students at a distance. In the second generation new, pedagogically enhanced materials were designed and developed via an industrial model specifically for distance education, but the accent remained on a traditional learning paradigm. In the third generation personal, competence based, interactive materials for learning communities are being designed and developed. This chapter first outlines the haracteristics of the first two generations. It then presents a framework for the design, development and delivery of distance education study materials according to the industrial approach. It concludes with a look at how this will change as we go to the third generation. In another chapter (Valcke, Kirschner & Bos) an environment for this new paradigm is worked out

    Mapping the internal recognition surface of an octanuclear coordination cage using guest libraries

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    Size and shape criteria for guest binding inside the cavity of an octanuclear cubic coordination cage in water have been established using a new fluorescence displacement assay to quantify guest binding. For aliphatic cyclic ketones of increasing size (from C5 to C11), there is a linear relationship between 螖G for guest binding and the guest鈥檚 surface area: the change in 螖G for binding is 0.3 kJ mol鈥1 脜鈥2, corresponding to 5 kJ mol鈥1 for each additional CH2 group in the guest, in good agreement with expectations based on hydrophobic desolvation. The highest association constant is K = 1.2 脳 106 M鈥1 for cycloundecanone, whose volume is approximately 50% of the cavity volume; for larger C12 and C13 cyclic ketones, the association constant progressively decreases as the guests become too large. For a series of C10 aliphatic ketones differing in shape but not size, 螖G for guest binding showed no correlation with surface area. These guests are close to the volume limit of the cavity (cf. Rebek鈥檚 55% rule), so the association constant is sensitive to shape complementarity, with small changes in guest structure resulting in large changes in binding affinity. The most flexible members of this series (linear aliphatic ketones) did not bind, whereas the more preorganized cyclic ketones all have association constants of 104鈥105 M鈥1. A crystal structure of the cage路cycloundecanone complex shows that the guest carbonyl oxygen is directed into a binding pocket defined by a convergent set of CH groups, which act as weak hydrogen-bond donors, and also shows close contacts between the exterior surface of the disc-shaped guest and the interior surface of the pseudospherical cage cavity despite the slight mismatch in shape
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